Improvement in punching-machines



6 H. PERKINS. Punching-Machines.

Patented July 7,1874.

IId,i.

UNITED "STATES PATENT OFFICE.

GEORGE H. PERKINS, OF'IHILADELPHIA,PENNSYLVANIA, ASSIGNOR TO HIMSELF AND JOSEPH LE GOMTE, OF NEWV YORK CITY, AND ATLANTIC .REFINING COMPANY, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN PUNCHlNG-MACHINES.

Specification forming part of Letters Patent No. 152,862, dated J uly 7, 1874; application filed March 18, 1874.

CASE

To all whom it may concern Be it known that I, GEORGE H. PERKINS, of the city of Philadelphia, Pennsylvania, have invented certain Improvements in Punchin g-Machines, of which the following is a specification:

The object of my invention is to trim a.

sheetmetal plate with perfect truth by the action of a punch and die, and to cut a strip or strips from the remnant of the plate simultaneously with the trimming operation; and I attain this object by combining springgripers A and supplemental cutters B and B with the punch D and its die F, as shown in the elevations, Figures 1 and 2, sectional view, Fig. 3, enlarged views, Figs. 4, 5, and 6, and perspective view, Fig. 7, of the accompan ying drawing.

The punching-machine to which my improvements are applied is of ordinary construction, the rod G, to which the punch is secured, sliding in bearings in a frame, H, and the open die F being secured to the bedplate I.

In trimming or punching out blanks from sheet-metal plates, such, for instance, as those used in the manufacture of transportation cans for petroleum, &c., it is difficult to prevent them from yielding to the pressure of the punch when placed over the open die, so that the cut edges are apt to be irregular, this being especially noticeable when shearpunches, such as that illustrated in the drawin g, are employed, and when, in order to pre vent waste of metal, the plates are trimmed close to their edges, and have very little hold upon the die. I have found that this objection can be entirely overcome by griping and holding the edges of the plate so as to prevent it from yielding to the pressure of the punch during the trimming operation, and that it is most advantageous to secure the gripers A to the punch, so that they may descend with the latter and gripe the plate before the cutting commences.

Each griper is serrated at its lower end, so that it may have a firm hold upon the plates, and it is arranged to slide, to a limited extent, between the edge of the punch and a plate, a, secured thereto, as shown in Fig. 4. A rubber or other spring, I), which is interposed between the upper bent end of each griper and a bar, (I, secured to the punch, forces the said griper downward, so that it shall be brought in contact with the edge of the sheet-metal plate in advance of the punch, and then permits the griper to yield as the punch descends, without relaxing its hold upon the plate. One cross-bar, d, serves for two gripers, and it may, if desired, have an inherent spring, and be caused to bear directly upon the said gripers.

If, as I prefer, a rubber spring, b, is used, it may be retained in place by pins 0 on the griper and bar (I, as shown in Fig. 5.

1t frequently happens, in trimming sheetmetal plates, that a portion of the remnant is y of sufficient width to be available in the manufacture of small articles, providing it can be detached at once, and without iiiivolving extra labor. In order to out such strips from the remnant, I attach supplemental spring cutters B to the edge of the punch, in the same manner as the gripers and corresponding fixed cutters B to the die or bedplate beneath, as shown in Figs. 2 and 6, so that when the punch descends, these cutters shall slit the edges of the plate to a sufficient depth to separate the desired strip or strips from the remnant when the latter is formed by the punch. The strip a: shown in Fig. 7, for instance, is separated from the narrow and worthless portion 9: of the remnant by two sets of cutters, B B, arranged at one end of the punch and die, and adjacent to the corners of the same.

I claim as my invention- 1. The gripers A, guided by and having a limited sliding movement on the edge of the punch, in combination with the cross-bar (Z,

secured to the said punch and the interposed In testimony whereof I have signed my springs I). name to this specification in the presence of 2. The spring-cutters B and fixed cutters two subscribing Witnesses.

B, combined. with the punch D and its die F, GEORGE IL PERKINS 1n the manner described, for the purpose of severing strips .00 from the remnant of the Vitnesses: sheet-metal plate acted on by the said punch V A. STEEL, and its die. HUBERT HowsoN. 

